Myopia or Nearsightedness

What Does it Mean to Have Myopia?

Myopia is a kind of refractive error—an eye disorder that affects the way light refracts within the eye. In an eye without myopia, light is focused onto the surface of the retina, and an image is conveyed to the brain via the optic nerve. An eye with myopia has a bit of trouble focusing light in the same way. That’s because a myopic eye is typically elongated, rather than resembling a perfect sphere. Or, its cornea may be a bit more steeply curved than normal. These myopic aspects of the eye cause light to focus on a point in front of the retina, rather than directly on it. And light that doesn’t hit the retina produces an unclear image in the brain.

Symptoms of Myopia

People with myopia can have difficulty clearly seeing a movie or TV screen, a whiteboard in school or while driving. Generally, myopia first occurs in school-age children. Because the eye continues to grow during childhood, it typically progresses until about age 20. However, myopia may also develop in adults due to visual stress or health conditions such as diabetes.

What Causes Myopia?

Scientists haven’t yet isolated exactly what causes myopia. We know that it runs in families—you’re more likely to be nearsighted if one or both of your parents are, too. But, in addition to genetics, environmental factors seem to play a role. Children who spend less time outside appear to be more prone to developing myopia, whereas those who spend more time outdoors have their risk of myopia reduced. Scientists speculate that a lack of exposure to bright sunlight may be what’s slowing the progression of myopia, but they don’t know exactly how this relationship functions.

A January 2021 study supports this theory, showing that COVID lockdowns—and the increase in time spent indoors by children ages 6–8—upped the prevalence of myopia by 1.4 to 3 times.

How to you test for Myopia?

Our Experts Eye Doctors can test for myopia during a comprehensive eye exam. First, they’ll test your unassisted visual acuity by having you read lines from a Snellen chart—that’s the big poster with rows of letters and numbers that get smaller as they go down the page. They’ll also have you look through a tool called a phoropter, which is fitted with several lenses. The doctor will lower sets of lenses in front of each of your eyes and ask you which lenses help you to see more clearly. They may use a couple more specialized tools, such as a retinoscope and/or autorefractor, to determine the strength of your eye prescription. Both of these tools shine a light into the eye and help the doctor to assess the degree of your myopia.

Myopia Treatment

People with myopia have several options available to regain clear distance vision. They include:

• Eyeglasses. For most people with myopia, eyeglasses are the primary choice for correction. Depending on the amount of myopia, you may only need to wear glasses for certain activities, like watching a movie or driving a car. Or, if you are very nearsighted, you may need to wear them all the time. Generally, a single-vision lens is prescribed to provide clear vision at all distances. However, patients over age 40, or children and adults whose myopia is due to the stress of near vision work, may need a bifocal or progressive addition lens. These multifocal lenses provide different powers or strengths throughout the lens to allow for clear vision in the distance and up close.
• Contact lenses. For some individuals, contact lenses offer clearer vision and a wider field of view than eyeglasses. However, since contact lenses are worn directly on the eyes, they require proper evaluation and care to safeguard eye health.
• Ortho-k or CRT. Another option for treating myopia is orthokeratology (ortho-k), also known as corneal refractive therapy (CRT). In this nonsurgical procedure, you wear a series of specially designed rigid contact lenses to gradually reshape the curvature of your cornea, the front outer surface of the eye. The lenses place pressure on the cornea to flatten it. This changes how light entering the eye is focused. You wear the contact lenses for limited periods, such as overnight, and then remove them. People with mild myopia may be able to temporarily obtain clear vision for most of their daily activities.
• Laser procedures. Laser procedures such as LASIK (laser in situ keratomileusis) or PRK (photorefractive keratectomy) are also possible treatment options for myopia in adults. A laser beam of light reshapes the cornea by removing a small amount of corneal tissue. The amount of myopia that PRK or LASIK can correct is limited by the amount of corneal tissue that can be safely removed. In PRK, a laser removes a thin layer of tissue from the surface of the cornea in order to change its shape and refocus light entering the eye. LASIK removes tissue from the inner layers, but not from the surface, of the cornea. To do this, a section of the outer corneal surface is lifted and folded back to expose the inner tissue. A laser then removes the precise amount of corneal tissue needed to reshape the eye. Then, the flap of outer tissue is placed back in position to heal.
• Other refractive surgery procedures. People who are highly nearsighted or whose corneas are too thin for laser procedures may be able to have their myopia surgically corrected. A doctor may be able to implant small lenses with the desired optical correction in their eyes. The implant can be placed just in front of the natural lens (phakic intraocular lens implant), or the implant can replace the natural lens (clear lens extraction with intraocular lens implantation). This clear lens extraction procedure is similar to cataract surgery but occurs before a cataract is present.
• Vision therapy for people with stress-related myopia. Vision therapy is an option for people whose blurred distance vision is caused by a spasm of the muscles that control eye focusing. Various eye exercises can improve poor eye focusing ability and regain clear distance vision.

People with myopia have a variety of options to correct vision problems. Our Expert Eye Doctor will help select the treatment that best meets the visual and lifestyle needs of the patient.